Abstract

We present our study on organic light-emitting diodes(OLEDs) in which outcoupling is enhanced based on a bilayer electrode consisting of a conductive low-index layer and micro-patterned indiumtin oxide (ITO) layers. Optical simulation reveals that the taper angle of an ITO pattern is among the most critical parameters influencing the outcoupling efficiency in the proposed structure. A fabrication method based on a lift-off process is then employed to control the taper angle of the ITO pattern to be in the optimal range. OLEDs with the proposed electrodestructure exhibit 50%–70% enhancement in external quantum efficiency over reference devices.

Received 20 March 2012Accepted 16 May 2012Published online 05 June 2012

Acknowledgments:

This research was supported in part by Samsung Mobile Display (SMD) through the SMD KAIST OLED Research Center Program, by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 20120000815), and by the Human Resource Training Project for Strategic Technology funded by the Korea Institute for Advancement of Technology.

Abstract

We present our study on organic light-emitting diodes(OLEDs) in which outcoupling is enhanced based on a bilayer electrode consisting of a conductive low-index layer and micro-patterned indiumtin oxide (ITO) layers. Optical simulation reveals that the taper angle of an ITO pattern is among the most critical parameters influencing the outcoupling efficiency in the proposed structure. A fabrication method based on a lift-off process is then employed to control the taper angle of the ITO pattern to be in the optimal range. OLEDs with the proposed electrodestructure exhibit 50%–70% enhancement in external quantum efficiency over reference devices.